Hello. I have a JDM K20a engine which has a pinging problem. The car is an EP3 Civic Type R. It has a couple of bolt on mods including: a Gruppe M intake, Fujitsubo exhaust and PLM headers which I recently installed (did not change pinging problem). It has around 93,000kms on the clock.

Pinging can also be called detonating or knocking. It basically just makes a clicking sound at a certain part of the rev range with a certain amount of throttle. It only happens when the car is maintaining a constant speed or accelerating slowly. It does not do it when accelerating hard. It is easy to replicate when travelling 60kms at 3000rpm in 4th gear.

Things I have tried already include: all types of fuels (98, 95, 91, Caltex, BP & Shell), Nulon octane boost and clean, Seafoam motor treatment, all servicing is up to date (changing spark plugs and oil does nothing), Compression is good (1370kPa average w/ <5% variation between cylinders), K&N air filter is cleaned regularly. The idle is a little rough at times. Not sure if this could be related somehow.

I've hit a wall having run out of ideas for things to try. Not sure what my next move should be. The car has been to a reputable Honda mechanic who put it on the dyno and listened to the car under load. They could not identify the problem. Plugging in a Kpro seemed to only make things worse.

Please help.